Physics

Problem

Two smooth blocks

A

and

B

of masses

2\,\text{kg}

and

3\,\text{kg}

respectively are placed one above the other inside an elevator that is accelerating upward at

3\,\text{m\,s}^{-2}

. The lower block

B

rests on the elevator floor while the upper block

A

is in direct contact with

B

. Neglect any friction between the blocks, and take

g = 9.8\,\text{m\,s}^{-2}

. a. (i) Draw separate free-body diagrams for each block in the non-accelerating (ground) frame of reference. b. (ii) Using the diagrams, find the normal reaction exerted by block

B

on block

A

. c. (iii) Hence determine the normal reaction exerted by the elevator floor on block

B

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